(a) Technical Field of the Invention
The present invention is related to an air cleaner for an engine adapted to a power mower, and more particularly, to one that prevents foreign matter such as weeds, dust, and pebbles from being sucked into the air cleaner to enable clean air to be fed to the engine continuously and prevent the foreign matter from contaminating the carburetor of the engine.
(b) Description of the Prior Art
The air cleaner for engines adapted to power mowers generally available in the market functions to introduce fresh air to be mixed with fuel for combustion and explosion in the engine to generate power. As illustrated in FIGS. 1 and 2 of the accompanying drawings, the power mower 1 is essentially comprised of a body 11, two front wheels 12, two rear wheels 13, an engine 14, a fuel tank 15 and a handle 16. Wherein, a cutting cylinder (not illustrated) is provided at the bottom of the body 11; both pairs of front wheels 12 and rear wheels 13 are respectively provided in the front and the rear of the body 11; the engine 14 and the fuel tank 15 are mounted on the top of the body 11; the handle 16 extends upwards from the rear of the body 11; a speed controller 151 is provided to the handle 16; and a conductor 152 is used to connect the speed controller 16 to the engine 14. Once the power mower operates, the fresh air is introduced through an air cleaner 2 into a carburetor 3 to mix with the fuel. The mixture is then imported into the engine 14 for combustion and explosion to create power to drive the cutting cylinder to revolve with the speed to be controlled by the speed controller 151, thus for the user to steer the handle 16 for mowing.
Referring to FIGS. 2 and 3, the air cleaner 2 includes a case 21, an air cleaner element 22 and a cover 23. Wherein, on one side of the case 21 which is closer to the carburetor 3 is provided with an air inlet 211, and a supplementary air inlet 212. In addition to admitting the air, the supplementary air inlet 212 also functions as a drain. A locking member 213 in a long oval shape extends upwards from the center of the case 21. An air outlet 214 is provided on the bottom of the locking member 213 and two locking posts 215 are each provided on both sides inside the locking member 213. The locking post 215 relates to a hollow pillar and is internally threaded. Furthermore, an air passage 216 connecting through the carburetor 3 is disposed below the case 21.
The air cleaner element 22 has a hollow center at its bottom for the insertions of the locking member 213 and both locking pillars 215 from the case 21. A trap 221 in the form of a piece of filtration cotton or paper is provided to the peripheral of the air cleaner element 22. A resilient washer 222 is provided on the lower circumference of the air cleaner element 22, and a locking hole 223 is disposed above the air cleaner element 22 at where in relation to the location of the locking pillar 215.
The cover 23 is a rectangular shape to cover up the case 21 and a through hole 231 is provided on top of the cover 23 in relation to the location of the locking pillar 215 to permit insertion of a fastener 24 for locking purposes.
As illustrated in FIG. 3 for the assembly of the air cleaner 2 of the prior art, the air cleaner element 22 is placed on the locking member 213 inside the case 21 with the locking holes 223 on the air cleaner element 22 located in relation to the locking post 215 and the resilient washer 222 below the air cleaner element 22 flushed to the case to prevent overflow of clean air. The cover 23 is then placed upon the case with the through hole 231 on top of the cover 23 located in relation to the locking hole 223 of the air cleaner element 22. The fastener 24 is inserted through the locking hole 223 of the air cleaner element 22 via the through hole 231 and locked to the locking post 215.
When the engine 14 is operating as illustrated in FIGS. 1 and 3, the ambient air enters into the case 21 through the air inlet 211 and the supplementary air inlet 212. Vapor and foreign matter carried by the air are filtered with the trap 221 for the vapors to condensate into drops to be drained out of the case 21 through the supplementary air inlet 212. As illustrated in FIGS. 1 and 2, the clean air passing through the trap 221 enters into the air passage 216 through the air outlet 214 to mix with the fuel by the carburetor 3 for keeping the engine 14 running.
However, foreign matter including weeds, dust and pebbles are usually present in the air fed to the power mower in operation. When the air around the air cleaner 2 enters into the case 21 through the air inlet 211 and the supplementary air inlet 212, the foreign matter will be usually sucked into the case 21 at the same time, and weeds and dust of a smaller size may pass through the air inlet 211 and the supplementary air inlet 212 may be intercepted by the trap 221; but larger sized matter may block the air inlet 211 resulting in a higher concentration of air-fuel mixture to discharge the higher volume of exhaust. Furthermore, it requires the user to remove the air cleaner 2 for cleaning. In serious cases, the engine will fail and the foreign matter will contaminate the carburetor 3.
As described above, the air inlet 211 is vulnerable to being blocked by weeds and dust resulting in an insufficient supply of fresh air to the carburetor 3 to discharge higher volume of exhaust. Frequent maintenance of the air filter also presents an inconvenience for the user.